Wines by the glass – keeping them fresh

Published by Sally on May 16, 2009

A version of this article first appeared in Drinks Business magazine, 2008.

Wine by the glass offerings have become increasingly important for on trade outlets as a point of differentiation, and as a mark of serious wine credentials. And as they expand, so does the marketplace offering bits of kit to preserve open bottles, from temperature-controlled cabinets, which blanket opened bottles with inert gas, to devices that pump out air.

Here’s the rub: as soon as the bottle is open, wine starts to oxidise. Full stop. All that any piece of kit will do is prolong the death.  But if you can keep a bottle fresh for three or four or five days, then it may well be worth its salt in terms of reduced wastage from selling a greater range, of sometimes better wines, by the glass.

If one accepts that any piece of kit is merely prolonging the inevitable, and the manufacturers claim varying degrees of success in terms of open-bottle longevity, then they can still be a profitable tool.  The manufacturers of Cruvinet cabinet system, for example, suggest the cost of their kit can be recouped in as little as two to three months, but this very much depends on the pre-equipment sales volume.


Russell Cocks, the restaurant manager at Pearl is happy with the two Cruvinet units they have, notwithstanding the £15,000-ish cost.  He said: “The nitrogen keeps wine as fresh as when they’re open, lasting about 5 weeks. But if it’s been sitting a few days, we’ll taste the first 50ml out of the tap to check it’s not oxidised.” With 36 still wines by the glass, including Tignanello, Château Musar and Cloudy Bay sauvignon blanc, Pearl is not messing about with its offer.

Selfridges has an Enomatic cabinet, which have been in the UK for just over a year.  Sommelier Dawn Davies said: “we have 52 wines on the machine, they can last up 21 days, depending on the wine. [But] no amount of nitrogen will protect an older wine.”  Indeed one restaurant owner said pinot noir was particularly susceptible to oxidation despite preservation systems.  

Enomatic can also be seen at Gerard Basset MW’s hotel, TerraVina. He said: “I don’t want to keep wine for too long once it’s opened, but it’s better to do something than nothing.”  

The Selfridges kit comes with a card operation system.  Customers put credit onto a card and can serve themselves from the machine, which adds a new element of interactivity. The card system can be a simple credit system, or, as David Sheedy, sales manager for Enomatic explained, it can incorporate “professional software for stock control, and which creates a database of customers’ choices.”

Newcomer onto the UK market, Ozwinebars is similar to Enomatic, with temperature controlled compartments, gas blanketing, and an optional card system. Ballpark costs are £10,000.


Long-time market leader in the field of wine preservation, with some 9,000 outlets in the UK using it, is Bermar’s Verre de Vin system.  This is also a fixed unit, and allows any number of bottles to be used.  Bottles are taken to table for service, and returned to their storage position via the unit, for push-button preservation. 

The £2,000-plus Verre de Vin uses vacuum technology to remove air from the wine. Bermar’s managing director Dave Marr is well aware of the challenges of removing too much air, saying it bruises the wine, adding: “After long research, we discovered there was a critical measure [of vacuum] we wanted to achieve.”  He emphasised the importance of resealing the bottle as part of the pouring service.

One of the big advantages of Verre de Vin is that it has a system for sparkling wines as well as still.  It injects carbon dioxide into the sparkling bottle ullage (empty space above the liquid) which, Marr argues, protects the remaining wine.  Cocks uses it at Pearl for five champagnes by the glass. 

Loch Fyne installed Verre de Vin in their 38 restaurants earlier this year. A spokesperson said they’d invested so they could start from scratch a wine by the glass programme. The chain reports a massive increase in sales such that the cost of installation has been recouped in six months.

A very different vacuum-based unit is Presorvac, a hand held device for both still and sparkling wines. Though logic beggars its effectiveness, the method of sparkling wine preservation is to pump air under pressure into the bottle to keep the carbon dioxide in the wine. 

It’s a small, battery-powered, eminently portable device which can be used on any number of bottles, and it could be just the thing where bar space is really tight. It uses colour coded stoppers for still and sparkling, and has a switch so the machine knows whether to suck or blow. 

Paul Fenner, managing director of Waiter’s Friend, which distributes Presorvac, said: “At just £165 plus VAT it’s affordable by any on trade outlet. Its arrival has encouraged a much broader spectrum of outlets to grow in confidence with their wine-by-the-glass service, whilst reducing wastage at the same time.”

Collateral benefits

The marketing aspect may be an even bigger bonus than any preservation capabilities.  Clare Young of on trade consultants Vintellect said: “I like them as a marketing tool – it does make the customer think about what you’re doing; and enables staff to engage in conversation. Wine preservation [equipment] opens dialogue and generates interest and buzz around what you’re doing.” Basset agreed, saying: “there’s a psychological benefit. People like to see the machine; they can be sure you care about your product.”  

At Pearl, Cocks generates additional sales. He said: “it’s a showpiece, a visual selling aid.  We serve a lighter lunch at the bar, and when customers see the Cruvinet, they often buy a glass.  If people are undecided, we can offer a few mills (millilitres) to taste. We may even gain a bottle sale from the taste.”

The technology

The Australian Wine Research Institute ‘s (AWRI) Peter Godden, group manager – industry development and support, and winemaker, explains:  “air is 20.95% oxygen and about 78% nitrogen. Nitrogen is ‘inert’ in that it doesn’t react with wine doesn’t dissolve in wine. Evacuating the air (with a vacuum pump), and replacing it with pure nitrogen, will therefore slow down oxidation.

“The application of a vacuum will remove some oxygen, but even with, say, a 90% vacuum you still have about 2% oxygen present in the headspace – much more than is needed to oxidise wine.

“Application of such a vacuum, especially if the bottle is then flushed with nitrogen, will draw volatile [aromatic] compounds out of the wine. The process of oxidation will be slowed, but you may be creating a ‘different’ wine, especially with highly aromatic varieties.” 

Evidently it’s better to do something than nothing. And the tangential marketing benefits appear as great, if not greater, than wine preservation, on which issue many have conservative views.  Suggestions of 4 to 5 days’ preservation are a-plenty, and if an outlet is taking longer to sell a bottle of wine, then it probably shouldn’t be on the wine by the glass offer.

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